This invention relates to magnetic recording media such as magnetic audio and video recording tapes, sheets and disks and, in particular, to magnetic recording media having a magnetic layer improved in its abrasive resistance and smooth-running properties and thus being well durable under severe conditions as usually encountered in VTR (video tape recorder) instruments.
It has been well-known in the art to incorporate carbon black into the magnetic layer primarily for antistatic purpose. However, where carbon black is added to a magnetic coating composition from which a magnetic layer is formed on a substrate to provide a magnetic recording medium, the carbon black affects adversely the dispersibility of the coating composition. If such a composition of poor dispersibility is applied on the surface of substrate, the resulting recording medium product will show poor coating surface properties, such as unduly high friction coefficient and roughness. In addition, the incorporation of carbon black may result in an undesirably increased viscosity of coating composition which lowers the coating operation efficiency. Moreover it is known also that, since the incorporation of carbon black reduces necessarily the relative porportion of a magnetic powder which may be present in the coating composition and hence in the magnetic layer, various electromagnetic performance properties such as video sensitivity of the recording medium are undesirably reduced by the addition of carbon black.